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On ADLP+ Bspec allows DC5/6 to be enabled while power well 2 is enabled.
Since the AUX and DDI power wells (except for port A/B) are also backed
by power well 2, this would suggest that DC5/6 can be enabled while any
of these AUX or DDI port functionalities are used. As opposed to this
AUX transfers will time out on ADLP TypeC ports while DC6 is enabled.

Until the restriction for DC5/6 is clarified in Bspec let's assume that
the intention is to allow for using these power states while pipe A/B is
enabled, but only for combo ports which can be used with eDP outputs.
Similarly assume that AUX transaction initiated by the driver on any port
requires DC states to be disabled.

Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Fixes: 88c48793

 ("drm/i915: Use separate "DC off" power well for ADL-P and DG2")
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230424200205.1732941-1-imre.deak@intel.com